Method and device for producing gauze borders on fabrics



Aug'.'13,'l957' R. oPLr-:TAL ETAL 2,302,488

METHOD AND DEVICE FDR PRDDUCING GAUZE BORDERS ON v FABRICS 2 Sheets-Sheet 1 Filed Aug. l5, 1955 Fig] Aug. 13, 1957 R. OPLETAL ETAL 2,802,488

METHOD AND DEVICE FOR PEODUCING GAUZE BORDERS 0N FABRICS Filed Aug. 15, 1955 2 Sheets-Sheet 2 MM 6*/ dig/7' United States Patent() f' METHOD AND DEVICE FOR PRODUCING GAUZE BORDERS ON FABRICS Application August 15, 19,55, Serial No. 528,322

Claims priority, application Czechoslovakia August 30, 1954 4 claims.A (c1. 139-54) The invention relates to a method and device for the production of a so-called imitation gauze ,on fabrics, in particular on fabrics produced on a shuttleless weaving loom. In a'fabric of this kind the Warp thread at the edge of the fabric is not surrounded by a weft thread and therefore is not retained in the fabric in la way usual for a fabric produced on a shuttle loom. The border vthreads may easily be pulled out either during the manufacture of the `fabric or when in use, because the weft threads are cut olf at the edge of the fabric, as if a fabric had been there cut and its edges not secured against fraying as by fa hem. In order to overcome this drawback and as a substitute for a genuine border of the fabric, an imitation `gauze is produced by means of a special device, in particular on fabrics manufactured on Ishuttleless weaving looms.

The securing of the warp threads by a gauze border is carried out by at least two warp threads, which are braided together around Ia weft thread so as to clamp the matter.

A known proces of this type employs three Warp threads for each gauze, of which two so-called braiding warp threads are positioned in the lower shed and a binding thread, passing between the braiding warp threads is positioned in the upper shed. The weft thread is inserted when the shed is open. When the shed 4is closed, the binding thread moves from the upper into the lower shed and lies underneath the plane of the two braiding threads which are permanently in the lower shed. The braiding threadsare then plaited together and, before 'a new shed is formed,the binding thread passes between the braiding threads whereupon it arrives again in the upper shed.

This gauze is objectionable because the borders of the fabric tend to increase in length quicker than the middle portion of the fabric, in particular in fabrics with a multiple weave in consequence of a larger number of binding knots. A still greater drawback consists in that during each formation of a shed, while the usual warp threads proceed from the upper shed into the lower shed, the binding thread ha-s to carry out rst la movement downwards andthen upwards which places higher requirements on the mechanism. The period during `which the shed is open, is thus shortened which is objectionable in particular in high speed weaving looms.

The method according to the invention removes the above drawbacks and consists therein, that the movement of the pair of braiding of warp threads and of the binding thread is derived from the movement of the harness frames, the weft threads which are successively inserted lying alternately above and underneath the pair of braiding warp threads, every other weft thread passing through la crossing point of the said pair of braiding warp threads.

The above, and other objects, features and advantages of the present invention, will be apparent in the following ICC detailed description of -a method and apparatus embodying the invention which is to be read in connection with the accompanying drawings which form a part hereof, and wherein:

Fig. l is a fragmentary diagrammatic plan View of a gauze border formed in accordance with an existing method for preventing pulling out of the end Warp threads of a fabric produced on a shuttleless weaving loom;

Fig. 2 is a graphic representation of the movements of the braiding warp threads and the binding warp thread during the production of the gauze border of Fig. l;

Fig. 3 is a view lsimilar to Fig. l, but :showing a gauze border formed in accordance with the method embodying the present invention;

Fig. 4 is a sectional view taken along the line A-A of Fig. 3;

Fig. 5 is a diagrammatic View of 'attachments for a shuttleless weaving loom to produce the gauze border of Figs. 3 and 4 in accordance with the present invention, such attachments being viewed in a direction perpendicular to the plane of the warp threads; and

Fig. 6 is a detailed View of a part of such attachments for effecting the crossing of the braiding warp threads, Isuch part of the attachments being viewed in a direction perpendicular to the View of Fig. 5.

Referring initially to Fig. l of the drawings, it will be `seen that, in a gauze border formed in accordance with an existing method, the braiding warp threads 2 and Z are positioned in the lower shed, while the binding thread 1 which is located laterally between the braiding warp threads is positioned in the upper shed. The weft thread 3 is inserted when the shed is open. When the shed is closed, the binding thread 1 moves from the upper shed into the lower shed and lies beneath the plane of the braiding warp threads Z'and 2 which are maintained in the lower shed. The braiding warp threads 2 :and 2 are then crossed or plaited together and, before a new shed is formed, the binding thread 1 is passed between the braiding warp threads to again arrive in the upper shed.

The gauze border of Fig. l is objectionable because the borders of the fabric formed in that way tend to increase in length faster than the middle portion of the fabric `during the weaving operation, and this disadvantage is particularly noted in the case of fabrics with a multiple weave. The existing gauze border of Fig. l has the further disadvantage of `requiring the binding thread 1, during each formation of a shed, to move first downward and then upwards, and such dual movement of the binding thread during each formationof the shed requires a fairly complex mechanism. Further, the period during which the shed is open for the reception of a weft thread is thereby shortened, and this is particularly objectionable in high speed weaving looms. The diagram of Fig. Zirepresents the movements ofthe warp threads 4 fand 4 and of the binding thread 5. The height v of the shed is plotted against the ordinate, While the plane m separates the upper shed from the lower shed. The depth s of the shed is plotted against the abscissa, the latter being simultaneously a scale measure of the time. The distance t indicates the time which is normally avail- -able for the insertion of the weft thread, that is, in the absence of the formation of the usual gauze border, while the distance t' indicates the shortened time that is available by reason of the required dual movement of the binding thread. By reason lof such shortening of the time available for the insertion of the weft thread, the retraction of the inserted weft thread, which is necessary with severed weft threads, is made far more difficult.

The formation of a gauze edge according to the invention is shown in Figs. 3 and 4 in which the plaiting or braiding warp threads are identied by the numerals Z a and 2 Iand thebinding thread is identified by the numeral 1, as in Fig. 1. The successive weft threads bear the reference numerals 3 and 3.

lt is apparent from the drawing that the weft threads are bound by the gauzes alternately in two different ways. When the Ished is reversed, the weft thread 3 is Woven in similar to Fig. 1, while during the next reversionof the shed the weft thread 3 is woven in in such 'a way that it lies between the crossed braiding warp threads 2, 2 lying on top and the binding thread 1, so that the weft thread 3 is rigidly clamped.

A device for carrying out the method according to the invention is shown diagrammatic-ally in Figs. 5 and 6.

In Fig. 5, which Irepresents an end view in the direction of the warp, the overall larrangement for the production of gauze borders is represented. The frames of the harness are identified by the numerals 6 and 6', and the warp threads are identified by the numerals 7 and 7 A needle 8 is secured in a carrier 24 on the frame 6', said needle carrying the binding thread 1. On the frame of the Weaving loom there is mounted ya casing 9 with a shaft 10 which receives its drive from the crank shaft of the weaving loom. An eccentric 11 is rigidly mounted on the shaft 10, said eccentric imparting reciprocal movement in a horizontal direction by means of its rod 12 to a rack 13, the teeth of which are not shown. The rack engages with a gear mounted at the lower end of 4a grooved spindle 14 and imparting reciprocal rotary movement thereto. A carrier 15 is mounted for Isliding movement on the spindle, said carrier being rigidly connected by means of a bracket 23 with an auxiliary frame 26 moving in synchronism with the harness frame 6, so that the carrier performs reciprocal movement with the frame 26. A gear 16 is mounted in the carrier 15 in such a way as to follow the movements thereof. The gear 16 litted on the spindle 14 is rotated therewith because of a key being mounted in its bore, said key engaging a groove in the spindle. The gear 16 engages with :a gear rack 21 (Fig. 6), provided on a rail 17. The rail 17 is provided with another gear rack 22 by means of which it engages a gear 19 which carries out free reciprocal Krotary movements on a pivot 18, the axis of which is perpendicular to the axis of the gear 16. The gear 19 meshes with a gear rack on another rail 17', The rails 17, 17 which in this way carry out reciprocal movements in opposite directions extending perpendicular to the direction of the warp, produce the crossing of the braiding warp threads 2, 2 which Iare suspended on the rails in points 25. The crossing takes place during the insertion of every other weft thread i. e. when the braiding warp threads are in the upper-shed.

We claim:

1. In a method for producing gauze borders on woven fabrics, particularly, on fabrics produced on a shuttleless weaving loom, and employing a pair of braiding warp threads and `a binding warp thread interwoven with the weft threads for the production of each gauze border; the steps of crossing the braiding warp threads at every other pick, and shedding said braiding warp threads and said binding warp thread in accordance with the shedding movement of respective harness frames handling the warp threads making up the fabric between the gauze borders to effect reversal of the positions of said braiding warp threads and said binding warp thread,

respectively, in the shed during successive openings of the shed, so that the successively inserted weft threads are positioned alternately above and below said pair of braiding warp threads with every other weft thread being located at a crossing point of said pair of braiding warp threads.

2. An attachment for producing gauze borders at the edges of a fabric woven on a loom having two oppositely moving harness frames for effecting rshedding of the warp threads entering into the fabric between the borders thereof; said attachment comprising a Vcarrier for receiving a binding warp thread connected to one of said harness `frames for movement with said one harness frame during shedding of the warp threads, an auxiliary frame moving with the other of said harness frames during shedding of the warp threads, and a carrier for a pair of braiding warp threads mounted on said auxiliary frame and having a pair of rails each receiving a related one of the braiding warp threads, said rails being reciprocablein opposite directions extending perpendicular to the direction of the warp threads, thereby to effect crossing of the braiding warp threads received by said rails.

3. An attachment for producing gauze borders at the edges of a fabric woven on a loom having two oppositely moving harness frames for effecting shedding of the warp threads entering into the fabric between the borders thereof; said attachment comprising a carrier for receiving .a binding warp thread connected to one of said harness frames for movement with said one harness frame during shedding of the warp threads, an auxiliary frame moving with the other of said harness frames during shedding of the warp threads, a carrier for a pair of braiding warp threads mounted on said auxiliary frame and having a pair of rails each receiving a related one of the braiding warp threads, said rails being reciprocable in opposite directions extending perpendicular to the direction of the warp threads, thereby to effect crossing of the braiding warp threads received by said rails, and means for effecting reciprocation of said rails in synchronism with the shedding movement of said auxiliary frame so that said rails complete a cycle of reciprocation in opposite directions whenever said auxiliary frame arrives at a predetermined one of its extreme shedding positions.

4. AnV attachment as in claim 3; wherein said means for effecting reciprocation ofl said rails includes a vertically xed, longitudinally grooved spindle rotatable about a vertical axis, means for effecting oscillatory rotation of said spindle in synchronism with the movements of the harness frames of the loom, and means operative to convert the oscillatory rotation of said spindle into reciprocation of Asaid rails in opposite directions and including a drive element movable with said carrier for the braiding warp threads in accordance with the movement of said auxiliary frame, said drive element being axially slidable on saidspindle and rotationally coupled with the latter.

References Cited in the file of this patent UNITED STATES PATENTS 936,445 Gordon Oct. 12, 1909 1,226,361 Niederwerfer May 15, 1917 1,872,9354 Gordon` Aug. 23, 1932 

